Radial Engine-Generator With Overhead Camshaft

ABSTRACT

A radial engine-generator includes an electric power generator and a radial engine. The radial engine-generator can be a mobile and portable unit, and is employable as a primary or back-up source of electric power at data centers, manufacturing facilities, electric vehicle charging stations, medical facilities, telecommunications, and residential neighborhoods, among many other applications. The electric power generator and radial engine are coupled together. The radial engine includes, among other components, multiple cylinders, multiple cylinder heads, and multiple overhead camshaft assemblies. The overhead camshaft assemblies are located at the cylinder heads and each include one or more camshafts. The camshaft(s) receive rotational drive input from a crankshaft of the radial engine. In certain implementations, camshaft carrier assemblies can be provided to support components of the overhead camshaft assemblies.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent..Application No. 63/215,548, with a filing date of Jun. 28, 2021, thecontents of which are hereby incorporated by reference in theirentirety.

INTRODUCTION

The present disclosure generally relates to engine-generators and, moreparticularly, to engine-generators that employ internal combustionengines of a radial reciprocating type.

In general, an engine-generator—also referred to as a genset—combines anelectric power generator and an engine together as a single piece ofequipment. Engine-generators can be equipped as mobile and portableunits that can be transported to their place of use via trailer orhelicopter, for instance. Applications of use include as a source ofprimary electric power or back-up electric power at data centers,manufacturing facilities, electric vehicle charging stations, medicalfacilities, telecommunications, and residential neighborhoods, amongmany others. Furthermore, certain engine-generators employ radialengines. Radial engines are a type of internal combustion engine inwhich pistons and cylinders of the radial engines radiate outwardly froma centrally-located crankshaft in a circumferential arrangement.

SUMMARY

In an embodiment, a radial engine-generator may include an electricpower generator and a radial engine. The radial engine is coupled to theelectric power generator. The radial engine may include multiplecylinders, multiple cylinder heads, multiple camshaft carrierassemblies, and multiple overhead camshaft assemblies. The cylinderheads are situated outboard of the cylinders. The camshaft carrierassemblies are mounted on the cylinder heads. The overhead camshaftassemblies are carried by the camshaft carrier assemblies. Each of theoverhead camshaft assemblies includes one or more camshafts. Thecamshaft(s) receives rotational drive input from a crankshaft of theradial engine.

In an embodiment, a radial engine-generator may include an electricpower generator and a radial engine. The radial engine is coupled to theelectric power generator. The radial engine may include multiplecylinders, multiple cylinder heads, multiple overhead camshaftassemblies, and multiple camshaft carrier assemblies. The cylinder headsare situated outboard of the cylinders. Each of the overhead camshaftassemblies includes one or more camshafts. The camshaft(s) receivesrotational drive input from a crankshaft of the radial engine. Each ofthe overhead camshaft assemblies may include a camshaft sprocket. Agearset assembly drives rotation of the camshaft sprocket by way of oneor more timing drive chains. The gearset assembly may include acrankshaft gear, a drive gear, a first working gear, and a sprocket. Thecrankshaft gear drives rotation of the drive gear. The drive gear, thefirst working gear, and the sprocket are mounted on a main shaft. Thedrive gear, the first working gear, and the sprocket rotate with themain shaft upon rotation of the main shaft. The sprocket drives movementof the timing drive chain(s). The camshaft carrier assemblies aremounted on the cylinder heads. Each of the camshaft carrier assembliescarries the camshaft(s), and each of the camshaft carrier assembliescarries an intake rocker arm and an exhaust rocker arm at each of theoverhead camshaft assemblies.

In an embodiment, a radial engine-generator may include an electricpower generator and a radial engine. The radial engine is coupled to theelectric power generator. The radial engine may include multiplecylinders, multiple coolant fluid passages, multiple cylinder heads,multiple overhead camshaft assemblies, and multiple camshaft carrierassemblies. Each of the coolant fluid passages partially or moreencircles each of the cylinders. The cylinder heads are situatedoutboard of the cylinders. Each of the overhead camshaft assembliesincludes one or more camshafts. The camshaft(s) receives rotationaldrive input from a crankshaft of the radial engine. Each of the overheadcamshaft assemblies may include a camshaft sprocket. A gearset assemblydrives rotation of the camshaft sprocket by way of one or more timingdrive chains. The gearset assembly may include a crankshaft gear, adrive gear, a first working gear, and a sprocket. The crankshaft geardrives rotation of the drive gear. The drive gear, the first workinggear, and the sprocket are mounted on a main shaft. The drive gear, thefirst working gear, and the sprocket rotate with the main shaft uponrotation of the main shaft. The sprocket drives movement of the timingdrive chain(s). The gearset assembly may further include a secondworking gear. The second working gear is driven to rotate by the firstworking gear. The second working gear drives rotation of other gears fortransferring rotational drive input to other overhead camshaftassemblies. The camshaft carrier assemblies are mounted on the cylinderheads. Each of the camshaft carrier assemblies carries the camshaft(s),and each of the camshaft carrier assemblies carries an intake rocker armand an exhaust rocker arm at each of the overhead camshaft assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more aspects of the disclosure will hereinafter be described inconjunction with the appended drawings, wherein like designations denotelike elements, and wherein:

FIG. 1 is a perspective view of an embodiment of a radialengine-generator;

FIG. 2 is a side view of the radial engine-generator;

FIG. 3 is a cross-sectional view of the radial engine-generator;

FIG. 4 is a front view of an embodiment of overhead camshaft assembliesthat can be equipped with a radial engine of the radialengine-generator;

FIG. 5 is an enlarged view of the overhead camshaft assemblies;

FIG. 6 is a segmented view of an assemblage of gears that can beemployed with the overhead camshaft assemblies;

FIG. 7 is a perspective sectional view of one of the overhead camshaftassemblies;

FIG. 8 is an enlarged sectional view of the overhead camshaft assembly;

FIG. 9 is an enlarged sectional view of the overhead camshaft assembly;

FIG. 10 is an enlarged sectional view of a cylinder head of the radialengine;

FIG. 11 is a perspective view of an embodiment of a camshaft carrierassembly of the radial engine;

FIG. 12 is a perspective view of an upper portion of an isolated pistonand cylinder construction of the radial engine;

FIG. 13 is a perspective view of the assemblage of gears that can beemployed with the overhead camshaft assemblies; and

FIG. 14 is another sectional view of the cylinder head of the radialengine.

DETAILED DESCRIPTION

Referring to the drawings, an embodiment of a radial engine-generator 10is presented in the figures and detailed in this description. The radialengine-generator 10 is of the radial internal combustion engine type,and can be employed in use as a source of primary electric power orback-up electric power at data centers, manufacturing facilities,electric vehicle charging stations, medical facilities,telecommunications, and residential neighborhoods, among many otherpotential applications. The radial engine-generator 10 can utilizenatural gas for combustion, for instance, or some other kind of gaseousand/or combustible fuel such as propane, methane, butane, gasoline,ethanol, alcohol, or the like, and can produce up to 1,000,000 Watts (W)of electricity in an embodiment with a single radial engine. In anembodiment with a multitude of radial engines, the radialengine-generator 10 can produce up to 3,500,000 W of electricity. Theradial engine-generator 10 could be a diesel engine in other examples.The radial engine-generator 10 is relatively lightweight and compact,and is suitable for use as a mobile and portable unit that can betransported via trailer or helicopter, as examples. Unlike pastengine-generators of the radial reciprocating type, the radialengine-generator 10 is equipped with overhead camshaft assemblies 12 forinitiating actuation of intake and exhaust valves. The radialengine-generator 10 exhibits enhanced effectiveness and efficiencycompared to the past engine-generators of the radial reciprocating type.

The radial engine-generator 10 can have various designs, constructions,and components in different embodiments depending upon—among otherpossible factors—the desired electric power output produced amid use. Inan embodiment of FIGS. 1-14 , for example, the radial engine-generator10 has, as its larger primary components, an electric power generator 14and a radial engine 16. The electric power generator 14 and radialengine 16 have a coupling between them for converting motive power ofthe radial engine 16 into electrical power at the electric powergenerator 14. The coupling transfers rotational output of the radialengine 16 to the electric power generator 14, such as to an internalarmature of the electric power generator 14. A torque-transmission unitcan be situated between the electric power generator 14 and the radialengine 16. One example of a generator unit that can be employed as theelectric power generator 14 in the radial engine-generator 10, accordingto an embodiment, is model MJB-400-MB4 provided by Marelli Motori ofArzignano (VI), Italy; still, other examples of generator units arepossible in other embodiments.

The radial engine 16 has nine pistons 18 and nine accompanying cylinders20 that are configured to span radially-outwardly from acentrally-located crankshaft 22; still, other embodiments could haveother quantities of pistons and cylinders. Piston rods 24 are connectedto the crankshaft 22 and, upon combustion at the cylinders 20, work todrive rotation of the crankshaft 22. The crankshaft 22 extends from theradial engine 16 to the electric power generator 14. A crankshaft gear23 is mounted on the crankshaft 22 and is driven to rotate thereby.Piston heads 28 reciprocate within the cylinders 20 and at combustionchambers 30. Cylinder heads 32 are situated radially-outboard of thecylinders 20. The cylinder heads 32 assist in the establishment of thecombustion chambers 30. With particular reference to FIGS. 7, 10, 12,and 14 , fluid coolant passages 34 are established within the cylinderheads 32 for coolant flow (e.g., water, water glycol mixture) at thecylinder heads 32 and thermal management of the radial engine 16.Coolant is introduced into the fluid coolant passages 34 via a coolantinlet 36, and coolant exits the fluid coolant passages 34 via a coolantoutlet 38. An external coolant pump can be equipped with the radialengine-generator 10 to provide movement of the coolant, according tosome embodiments. Immediately downstream of the coolant inlet 36, asection of the fluid coolant passages 34 circumferentially encircles anupper region of a first cylinder wall 39 of the cylinder 20. Here, asecond cylinder wall 41 helps establish the fluid coolant passage 34 forthe encircling. The second cylinder wall 41 is radially-outboard of saidfirst cylinder wall 39, and hence constitutes an outer wall relativethereto. The first and second cylinder walls 39, 41 establish adouble-wall construction with the fluid coolant passage 34 definedtherebetween. An individual fluid coolant passage 34 exhibits an axialoverlapping relationship with an individual cylinder 20. This section ofthe fluid coolant passages 34 helps ensure that the upper region of thefirst cylinder wall 39 is subject to coolant flow and hence benefitsfrom the attendant heat reductions.

With reference now to FIGS. 10 and 14 , in order to facilitate mountingand seating at the first cylinder wall 39 and second cylinder wall 41,as well as to facilitate and permit coolant flow thereat, a first set ofprotrusions 43 extends from the first cylinder wall 39 and a somewhatcomplementary second set of protrusions 45 extends from the secondcylinder wall 41. The first set of protrusions 43 projectsradially-outwardly from the first cylinder wall 39, and the second setof protrusions 45 projects radially-inwardly from the second cylinderwall 41. The first set of protrusions 43 includes a multitude ofindividual protrusions 43 that are spaced circumferentially apart fromone another with circumferentially-spanning clearances therebetween foraxially-directed flow of coolant. Similarly, the second set ofprotrusions 45 includes a multitude of individual protrusions 45 thatare spaced circumferentially apart from one another withcircumferentially-spanning clearances therebetween for axially-directedflow of coolant. In assembly and mounting, the first and second sets ofprotrusions 43, 45 come into abutment with one another and individualprotrusions 43, 45 are engaging against each other. The respective axialclearances are in alignment upon assembly and mounting and togetherdefine axial passages 47 for upward-axial flow of coolant thereat.Multiple seals 49 in the form of o-rings can be situated and seated atan interface between the first and second cylinder walls 39, 41 axiallyopposite the first and second sets of protrusions 43, 45. Withparticular reference now to FIG. 10 , an intake valve 40, an intakespring 42, and an intake rocker arm 44 work together to promptintroduction of air into the combustion chamber 30 amid use of theradial engine 16. In a similar fashion, an exhaust valve 46, an exhaustspring 48, and an exhaust rocker arm 50 work together to promptexpulsion of exhaust from the combustion chamber 30 amid use of theradial engine 16.

The overhead camshaft assemblies 12 serve to effect opening and closingactuation actions of the intake and exhaust valves 40, 46. An individualoverhead camshaft assembly 12 constitutes a single overhead camshaftarrangement, and one overhead camshaft assembly 12 installation issituated at each piston/cylinder of the radial engine 16-there are nineoverhead camshaft assemblies 12 in total in the embodiment of thefigures to correspond to the nine pistons 18 and cylinders 20.Rotational drive input for each overhead camshaft assembly 12 isreceived from the crankshaft 22 and crankshaft gear 23, and rotationaldrive output from each overhead camshaft assembly 12 is delivered to theintake and exhaust rocker arms 44, 50. For the sake of brevity, a singleoverhead camshaft assembly 12 is subsequently described; in thisembodiment at least, the nine overhead camshaft assemblies 12 eachexhibit the same design and construction and components with respect toone another.

The overhead camshaft assembly 12 can have various designs,constructions, and components in different embodiments dependingupon—among other possible factors—the arrangement of downstream andupstream components in terms of input and output to and from theoverhead camshaft assembly 12. In the embodiment presented by thefigures, and with general reference to FIGS. 4-11 and 13 , the overheadcamshaft assembly 12 includes an assemblage of gears (or gearsetassembly) that receive rotational drive and torque input from thecrankshaft 22 and that deliver rotational drive and torque output to theintake and exhaust rockers arms 44, 50. The assemblage of gears can havevarious designs, constructions, and components in various embodiments.The overhead camshaft assembly 12, per this embodiment, includes a drivegear 53, a first working gear 55, a sprocket 54, a main shaft 56, asecond working gear 57, a camshaft sprocket 58, one or more timing drivechains 60, and a camshaft 62. Still, the overhead camshaft assembly 12could have more, less, and/or different components in other embodiments.

With general reference to FIGS. 4-9, 11, and 13 , the drive gear 53 ismounted on the main shaft 56. A set of external gear teeth of the drivegear 53 is directly engaged by and meshes with a set of external gearteeth of the crankshaft gear 23. The crankshaft gear 23 hence drivesrotation of the drive gear 53, which in turn incites rotation of themain shaft 56. The sprocket 54 is mounted on the main shaft 56 at anaxially-offset position relative to the drive gear 53. Similarly, thefirst working gear 55 is mounted on the main shaft 56 at anaxially-offset position relative to the drive gear 53, as well asrelative to the sprocket 54, and is axially sandwiched therebetween. Themain shaft 56 hence constitutes a common shaft for the drive gear 53,sprocket 54, and first working gear 55. Due to their mounting, thesprocket 54 and first working gear 55 rotate with the main shaft 56 andas the main shaft 56 is incited to rotate by the drive gear 53. A set ofexternal gear teeth of the sprocket 54 directly engages and meshes withthe timing drive chain 60. The sprocket 54 hence drives movement of thetiming drive chain 60.

The first working gear 55 is one gear amongst a set of other gears 52that are circumferentially arranged around the second working gear 57.The other gears 52, like the first working gear 55, are mounted onrespective main shafts 56. But unlike the first working gear 55, theother gears 52 incite rotation of their respective main shafts 56. Withparticular reference to FIGS. 6 and 8 , the first working gear 55 hasits set of external gear teeth directly engaged and meshed with a set ofexternal gear teeth of the second working gear 57. The first workinggear 55 hence drives rotation of the second working gear 57. The secondworking gear 57 has a mounting at the crankshaft 22 via a set of workingbearings 59, and is hence not driven to rotate by the crankshaft 22 andinstead can spin freely thereabout. Rotation of the second working gear57 is driven solely by the first working gear 55. The second workinggear 57 has its set of external gear teeth directly engaged and meshedwith a set of external gear teeth of the other gears 52 of otheroverhead camshaft assemblies 12 of the radial engine 16. The secondworking gear 57 hence drives rotation of the other gears 52, excludingthe first working gear 55. The first working gear 55 can largely orwholly replicate the other gears 52 in terms of shape and dimensions.The other gears 52, in turn, incite rotation of their respective mainshafts 56, which causes rotation of their respective sprockets 54 thatare also mounted on the respective main shafts 56. In this way, rotationand torque is transferred from the single drive gear 53, to the firstworking gear 55, to the second working gear 57, and to the other gears52. Moreover, certain gears of the assemblage can constitute a sectionor more of a planetary gear set; for instance, the second working gear57 can constitute a sun gear, while the other gears 52 can constitutethe accompanying planet gears.

It has been shown that this embodiment of the assemblage of gears morereadily facilitates torque transfer and rotational drive output from thecrankshaft gear 23 and, ultimately, to the sprockets 54 and camshaftsprockets 58 in an efficient and effective manner, while minimizingfriction generation among contact surfaces of the assemblage of gears.This has been found to beneficially minimize the required use anddemands of bearings in the assemblage.

The camshaft sprocket 58 is mounted on the camshaft 62, and drivesrotation of the camshaft 62. A set of camshaft external gear teeth ofthe camshaft sprocket 58 is directly engaged by and mesh with the timingdrive chain 60. The timing drive chain 60 hence drives rotation of thecamshaft sprocket 58. The timing drive chain 60 is an endless loopengaged around and spanning between the sprocket 54 and the camshaftsprocket 58. The timing drive chain 60 can be composed of a metalmaterial. In the embodiment here, there is a single timing drive chain60 to transfer rotational drive, but in other embodiments there could beother quantities, including dual or more timing drive chains 60. To drawthe timing drive chain 60 taut and tight, and maintain tautness andtightness, a tensioner assembly 70 (FIG. 5 ) is furnished along theextent of the timing drive chain 60. The tensioner assembly 70 includesan idler gear 72 that is spring-biased against the timing drive chain60.

The camshaft 62 physically interacts with the intake rocker arm 44 andthe exhaust rocker arm 50 in order to cause opening and closingactuation actions of the intake valve 40 and the exhaust valve 46. Withspecific reference to FIG. 9 , the camshaft 62 has an elongated extentthat spans longitudinally from a first end 76 adjacent the camshaftsprocket 58 to a second end 78 adjacent the installation of the intakeand exhaust rocker arms 44, 50. The camshaft 62 is located outboard ofthe combustion chamber 30. An outboard housing 80 encloses the camshaft62. The camshaft 62 has an intake lobe 82 and an exhaust lobe 84. Theoutboard housing 80 can be made-up of multiple walls. The intake andexhaust lobes 82, 84 are axially offset relative to each other. Theintake and exhaust lobes 82, 84 are radial-outward protrusions that comeinto respective abutment with the intake rocker arm 44 and the exhaustrocker arm 50 at alternate times amid use of the overhead camshaftassembly 12.

Furthermore, in order to support and carry certain components of theoverhead camshaft assemblies 12, a multitude of camshaft carrierassemblies 86 (also referred to as valvetrain carrier assemblies) aresituated outboard of the cylinder heads 32. A single camshaft carrierassembly 86 is mounted to each of the cylinder heads 32. The mountingcan be via bolting. The camshaft carrier assemblies 86 are separate anddistinct components with respect to the cylinder heads 32. The camshaftcarrier assemblies 86, in general, have proven to facilitate packagingof components of the overhead camshaft assemblies 12 and arrangementthereof, and facilitate installation of the overhead camshaft assemblies12 to the cylinder heads 32. The camshaft carrier assemblies 86 supportmounting of certain components of the overhead camshaft assemblies 12thereto. The camshaft carrier assemblies 86 can have various designs,constructions, and components in various embodiments depending at leastin part upon the design and construction and components of the overheadcamshaft assemblies subject to support.

In the embodiment presented in the figures, and with reference to FIGS.9 and 11 , an individual camshaft carrier assembly 86 includes amultitude of segmented plates 88, or structural walls. Carrier bearingassemblies 90 are held in the segmented plates 88 and engage thecamshaft 62 to support rotation thereof. The camshaft 62 and bearingassemblies 90 are seated in a lower carrier portion 92 of the camshaftcarrier assembly 86, with upper carrier portions 94 bolted thereto tosecure placement of the camshaft 62 and carrier bearing assemblies 90.The lower carrier portion 92 can be bolted directly to a respectivecylinder head 32. The camshaft carrier assembly 86 and its segmentedplates 88 carry and support placement and securement of the camshaft 62.Further, the camshaft carrier assembly 86 carries and supports placementand securement of the intake rocker arm 44 and the exhaust rocker arm 50in assembly and installation. Pivot shafts 96 of the intake and exhaustrocker arms 44, 50 are mounted at the camshaft carrier assembly 86.

It is to be understood that the foregoing is a description of one ormore aspects of the disclosure. The disclosure is not limited to theparticular embodiment(s) disclosed herein, but rather is defined solelyby the claims below. Furthermore, the statements contained in theforegoing description relate to particular embodiments and are not to beconstrued as limitations on the scope of the disclosure or on thedefinition of terms used in the claims, except where a term or phrase isexpressly defined above. Various other embodiments and various changesand modifications to the disclosed embodiment(s) will become apparent tothose skilled in the art. All such other embodiments, changes, andmodifications are intended to come within the scope of the appendedclaims.

As used in this specification and claims, the terms “e.g.,” “forexample,” “for instance,” “such as,” and “like,” and the verbs“comprising,” “having,” “including,” and their other verb forms, whenused in conjunction with a listing of one or more components or otheritems, are each to be construed as open-ended, meaning that the listingis not to be considered as excluding other, additional components oritems. Other terms are to be construed using their broadest reasonablemeaning unless they are used in a context that requires a differentinterpretation.

1. A radial engine-generator, comprising: an electric power generator; aradial engine coupled to said electric power generator, said radialengine comprising: a plurality of cylinders; a plurality of cylinderheads situated outboard of said plurality of cylinders; a plurality ofcamshaft carrier assemblies mounted on said plurality of cylinder heads;and a plurality of overhead camshaft assemblies carried by saidplurality of camshaft carrier assemblies, each of said plurality ofoverhead camshaft assemblies including at least one camshaft, said atleast one camshaft receiving rotational drive input from a crankshaft ofsaid radial engine.
 2. The radial engine-generator as set forth in claim1, wherein each of said plurality of overhead camshaft assembliesincludes a camshaft sprocket mounted to said at least one camshaft, saidat least one camshaft having an intake lobe and an exhaust lobe.
 3. Theradial engine-generator as set forth in claim 2, wherein each of saidplurality of overhead camshaft assemblies includes at least one timingdrive chain, said at least one timing drive chain engaging said camshaftsprocket.
 4. The radial engine-generator as set forth in claim 1,wherein each of said plurality of overhead camshaft assemblies includesa camshaft sprocket, and wherein a gearset assembly drives rotation ofsaid camshaft sprocket via at least one timing drive chain, said gearsetassembly includes a crankshaft gear, a drive gear, a first working gear,and a sprocket, said crankshaft gear drives rotation of said drive gear,said drive gear and said first working gear and said sprocket aremounted on a main shaft and co-rotate therewith, and said sprocketdrives movement of said at least one timing chain.
 5. The radialengine-generator as set forth in claim 4, wherein said gearset assemblyincludes a second working gear that is driven to rotate by said firstworking gear, said second working gear drives rotation of other gearsfor transferring rotational drive input to other overhead camshaftassemblies of said plurality of overhead camshaft assemblies.
 6. Theradial engine-generator as set forth in claim 5, wherein said secondworking gear is mounted at said crankshaft via a set of workingbearings.
 7. The radial engine-generator as set forth in claim 1,wherein a fluid coolant passage at least partially encircles each ofsaid plurality of cylinders, said fluid coolant passage establishedbetween a first cylinder wall of said plurality of cylinders and asecond cylinder wall of said plurality of cylinders.
 8. The radialengine-generator as set forth in claim 7, wherein said first cylinderwall has a first set of protrusions and said second cylinder wall has asecond set of protrusions, said first set of protrusions projectingradially-outwardly of said first cylinder wall, said second set ofprotrusions projecting radially-inwardly of said second cylinder wall,said first set of protrusions and said second set of protrusions cominginto engagement with one another and establishing a set of axialpassages thereamong for fluid coolant flow.
 9. The radialengine-generator as set forth in claim 1, wherein each of said pluralityof camshaft carrier assemblies includes a plurality of segmented platesmounted on said plurality of cylinder heads, said plurality of segmentedplates carrying said at least one camshaft of said plurality of overheadcamshaft assemblies.
 10. The radial engine-generator as set forth inclaim 1, wherein each of said plurality of camshaft carrier assembliescarries said at least one camshaft of said plurality of overheadcamshaft assemblies, and carries an intake rocker arm and an exhaustrocker arm at each of said plurality of overhead camshaft assemblies.11. A radial engine-generator, comprising: an electric power generator;a radial engine coupled to said electric power generator, said radialengine comprising: a plurality of cylinders; a plurality of cylinderheads situated outboard of said plurality of cylinders; a plurality ofoverhead camshaft assemblies, each of said plurality of overheadcamshaft assemblies including at least one camshaft, said at least onecamshaft receiving rotational drive input from a crankshaft of saidradial engine, each of said plurality of overhead camshaft assembliesincluding a camshaft sprocket, a gearset assembly drives rotation ofsaid camshaft sprocket via at least one timing drive chain, said gearsetassembly includes a crankshaft gear, a drive gear, a first working gear,and a sprocket, said crankshaft gear drives rotation of said drive gear,said drive gear and said first working gear and said sprocket aremounted on a main shaft and co-rotate therewith, and said sprocketdrives movement of said at least one timing chain; and a plurality ofcamshaft carrier assemblies mounted on said plurality of cylinder heads,each of said plurality of camshaft carrier assemblies carrying said atleast one camshaft of said plurality of overhead camshaft assemblies,and each of said plurality of camshaft carrier assemblies carrying anintake rocker arm and an exhaust rocker arm at each of said plurality ofoverhead camshaft assemblies.
 12. The engine-generator radial engine asset forth in claim 11, wherein said gearset assembly includes a secondworking gear that is driven to rotate by said first working gear, saidsecond working gear drives rotation of other gears for transferringrotational drive input to other overhead camshaft assemblies of saidplurality of overhead camshaft assemblies.
 13. The engine-generatorradial engine as set forth in claim 12, wherein said second working gearis mounted at said crankshaft via a set of working bearings.
 14. Theengine-generator radial engine as set forth in claim 11, wherein a fluidcoolant passage at least partially encircles each of said plurality ofcylinders, said fluid coolant passage established between a firstcylinder wall of said plurality of cylinders and a second cylinder wallof said plurality of cylinders.
 15. The engine-generator radial engineas set forth in claim 14, wherein said first cylinder wall has a firstset of protrusions and said second cylinder wall has a second set ofprotrusions, said first set of protrusions projecting radially-outwardlyof said first cylinder wall, said second set of protrusions projectingradially-inwardly of said second cylinder wall, said first set ofprotrusions and said second set of protrusions coming into engagementwith one another and establishing a set of axial passages thereamong forfluid coolant flow.
 16. The engine-generator radial engine as set forthin claim 11, wherein each of said plurality of camshaft carrierassemblies includes a plurality of segmented plates mounted on saidplurality of cylinder heads.
 17. A radial engine-generator, comprising:an electric power generator; a radial engine coupled to said electricpower generator, said radial engine comprising: a plurality ofcylinders; a plurality of coolant fluid passages, each of said pluralityof coolant fluid passages at least partially encircling each of saidplurality of cylinders; a plurality of cylinder heads situated outboardof said plurality of cylinders; a plurality of overhead camshaftassemblies, each of said plurality of overhead camshaft assembliesincluding at least one camshaft, said at least one camshaft receivingrotational drive input from a crankshaft of said radial engine, each ofsaid plurality of overhead camshaft assemblies including a camshaftsprocket, a gearset assembly drives rotation of said camshaft sprocketvia at least one timing drive chain, said gearset assembly includes acrankshaft gear, a drive gear, a first working gear, and a sprocket,said crankshaft gear drives rotation of said drive gear, said drive gearand said first working gear and said sprocket are mounted on a mainshaft and co-rotate therewith, and said sprocket drives movement of saidat least one timing chain, said gearset assembly further includes asecond working gear that is driven to rotate by said first working gear,said second working gear drives rotation of other gears for transferringrotational drive input to other overhead camshaft assemblies of saidplurality of overhead camshaft assemblies; and a plurality of camshaftcarrier assemblies mounted on said plurality of cylinder heads, each ofsaid plurality of camshaft carrier assemblies carrying said at least onecamshaft of said plurality of overhead camshaft assemblies, and each ofsaid plurality of camshaft carrier assemblies carrying an intake rockerarm and an exhaust rocker arm at each of said plurality of overheadcamshaft assemblies.
 18. The engine-generator radial engine as set forthin claim 17, wherein each of said plurality of fluid coolant passages isestablished between a first cylinder wall of said plurality of cylindersand a second cylinder wall of said plurality of cylinders.
 19. Theengine-generator radial engine as set forth in claim 17, wherein each ofsaid plurality of camshaft carrier assemblies includes a plurality ofsegmented plates mounted on said plurality of cylinder heads.